How to force an image to be always at the center of tikz environment?

Question

I have an image that is inserted into the text using tikzpicture environment. I want to add some text and shapes to the left of the picture that is out of the picture's scope. This action moves the picture to the right and the picture is not centered anymore. How can I force the picture to be always horizontally aligned in tikzpicture environment? I use these codes:

\begin{figure}[htbp]
    \centering
\begin{tikzpicture}[show grid]      \node[anchor=south west,inner sep=0] (image) at (0,0) {\includegraphics[width=0.7\textwidth]{figures/airfoil.pdf}};
        \node (1)  at (-1,5) {SOME TEXT}; %by adding this, the picture is not aligned anymore
    \end{tikzpicture}
\end{figure}

Answer 1

Option overlay can be used (e.g. for \node or with the scope environment) to add stuff that is not used for the bounding box calculation:

\documentclass{article}
\usepackage{graphicx}
\usepackage{ribbonproofs}
\usepackage{tikz}
\begin{document}
\begin{figure}
  \centering
  \begin{tikzpicture}[show grid]
    \node[anchor=south west,inner sep=0] (image) at (0,0)
      {\includegraphics[width=0.7\textwidth]{example-image}};
    \begin{scope}[overlay]
      \node (1)  at (-1,5) {SOME TEXT};
    \end{scope}
  \end{tikzpicture}
\end{figure}
\end{document}